Certain metal salts of dithiocarbamic acid have found extensive commercial application and are manufactured in large quantities. A general characteristic of the known processes for the manufacture of these salts is the voluminous coproduction of waste water streams containing dithiocarbamates and sulfur-containing decomposition products thereof. Should this waste water be directly discharged into surface water, for example, lakes, rivers or streams, such waters may become toxic to fish.
Several methods of reducing the fish toxicity of industrial waste water from the manufacture of dithiocarbamates are known. In the method of precipitation of neutralized waste water with the aid of zinc or ferric ions, solids are produced which are difficult and costly to filter and dispose of. Oxidation processes for reducing fish toxicity of this waste water require the use of costly oxidizing agents and such processes also produce solid waste containing toxic material.
Increasing demands by governmental agencies and the public dictate the need to provide less costly and more effective methods to detoxify industrial waste water and to substantially decrease this form of environmental pollution.